1. Field of the Invention
This invention relates generally to computer peripherals, and more particularly, to an orthopedic mouse designed to prevent diseases associated with the use of the computer mouse (e.g. tendinitis, bursitis, and carpal tunnel syndrome).
2. Brief Description of the Prior Art
Computer cursors are generally controlled by a manually manipulated pointing device connected to a computer, such as a mouse, trackball, touch pad, digitizing tablet or the like. The mouse includes a housing that is moved on a flat, stationary surface. The housing contains a motion sensor on its bottom side for tracking movement of the mouse, either as a single button or a plurality of buttons on or near the front edge thereof, and circuitry for electrically communicating with an attached computer. When the mouse is moved on a support surface, the cursor moves in a corresponding direction. When the buttons are pressed, certain actions can be performed, depending on the software application using the mouse. The internal components and electrical and software operations of computer mice are well known in the art.
Typical computer mice, such as the one shown in U.S. Pat. No. D302,426 to Bradley et al., are substantially wider than they are tall, and have generally symmetrical sides so that they can be used by either the right or the left hand. Some mice are specially shaped for providing an optimal fit for a user""s right hand. The mouse shown in U.S. Pat. No. D328,597 to Clouss, and sold under the trademark xe2x80x9cMouseManxe2x80x9d by Logitech Inc. in Fremont, Calif., has a slightly angled but generally horizontal top surface for supporting the fingers and palm of a right hand. The Microsoft Mouse, Version 2, sold by Microsoft Corporation in Redmond, Wash., includes a concave left side for closely engaging the base of the thumb and palm of a right hand. The mouse shown in U.S. Pat. No. 4,862,165 to Gart includes a surface for supporting some fingers in substantially curled positions. Some ergonomic mice, including the Logitech MouseMan(trademark), are also made in left-handed versions.
Most prior art mice have a generally horizontal, primary supporting surface for supporting a hand in a horizontal position, as exemplified by the drawing figures of U.S. Pat. No. 5,157,381 to Cheng, and the drawings in the user""s manual of the Microsoft Mouse. However, such prior art mice force the hand, wrist, and forearm to be twisted 80 to 90 degrees out of their natural and relaxed positions, and require constant muscular force to be applied to the hand, wrist, and forearm to maintain their positions. For a three-button mouse, the fore, middle, and ring fingers must be kept in constant tension to prevent them from resting too heavily on the buttons and depressing them inadvertently. A horizontal hand holding a prior art mouse is supported on the desk by only a small area at the wrist on the little finger side, so that a pressure sore may develop thereon. The total effort and discomfort may not seem great at first, but when these mice are used over a prolonged and continuous period of time, users may get diseases associated with the use of the computer mouse (e.g. tendinitis, bursitis, and carpal tunnel syndrome), experience fatigue, discomfort, and even pain in the hand and wrist.
U.S. Pat. No. 5,576,733 discloses an ergonomic computer mouse which includes an upright, primary finger supporting surface for supporting all of the fingers of an upright hand in straight positions in an upright stack. An opposite thumb-supporting surface is provided for supporting the thumb. This arrangement ostensibly provides greater comfort. However, neither the mouse disclosed in the ""733 Patent, nor any other existing computer mice will support the hand in the optimal xe2x80x9cposition of functionxe2x80x9d (also referred to as the xe2x80x9cphysiological positionxe2x80x9d) in which the musculature of the hand and forearm are at total rest. Maintaining the hand in a xe2x80x9cpincerxe2x80x9d position to support both the hand and the forearm in a vertical position requires effort.
A detailed discussion of the xe2x80x9cposition of functionxe2x80x9d may be found in, for example, THE HAND, Volume II, Chapter 53, pp.497-501, 1985, published by W. B. Saunders Company, the disclosure of which is hereby incorporated by reference as though fully set forth herein. The position of function relates to the position of the hand at rest, which assumes a certain position. This is largely a mid-position of the range of motion of each and every joint, including the wrist, and rotation of the forearm. The forearm is halfway between pronation and supination. The wrist is in about 20xc2x0 of dorsiflexion and 10xc2x0 of ulnar flexion. The fingers are slightly flexed in each of their joints, the index being flexed least and the little finger being flexed the most. The thumb is forward from the hand in partial opposition and its joints are also partially flexed. A more precise description of the position of function can be made with regard to the thumb. In this position, the angle between the first and second metacarpal is about 45xc2x0. Each and every xe2x80x9cposition of functionxe2x80x9d must endeavor to bring together a number of favorable conditions that are not always compatible with each other. They are those that place the joints in a position in which grasp is easy, in which stiffness is less likely to occur, and, finally, in which eventual stiffness will permit preservation of movements of small aptitude, in a useful range. To that concept we add a concept from the medical field: a position of work used during a prolonged period constitutes a form of immobilization (in function). xe2x80x9cThere does not exist a xe2x80x98position of functionxe2x80x99 in immobility; the function of the hand necessarily involves movement.xe2x80x9d THE HAND, Vol. II, Chapter 53 at 501.
In accordance with the above, it is an object of the present invention to provide an orthopedic computer mouse that is shaped to allow a hand holding it to remain in physiological position or position of function, i.e., a natural, untwisted, and relaxed position.
It is another object of the present invention to provide an orthopedic computer mouse that is designed to prevent diseases (e.g. tendinitis, bursitis, and carpal tunnel syndrome), and that minimizes or eliminates fatigue, discomfort, and pain even after prolonged and continuous use.
It is still another object of the present invention to provide an orthopedic computer mouse that may be sized to fit an individual user based upon the user""s hand measurements.
It is yet another object of the present invention to provide an orthopedic computer mouse which may be provided in both right and left-handed versions.
It is still another object of the present invention to provide an orthopedic computer mouse which is xe2x80x9cinnocuous,xe2x80x9d i.e., a computer mouse which has no adverse effect on, or which is harmless to the user.
In accordance with the above objects and additional objects that will become apparent hereinafter, the present invention provides an orthopedic computer mouse which can be translated over a support surface, the mouse adapted for supporting the hand in the xe2x80x9cposition of functionxe2x80x9d or xe2x80x9cphysiological position.xe2x80x9d The form of the orthopedic mouse in accordance with the invention has been developed from an imprint of the human hand realized in the position of function. The mouse comprises a bottom surface, a forward end, a rear end, and opposite sides, and a generally hemispherical surface for supporting the fingers of a hand in a generally elevated orientation relative to the support surface with the little finger located at a first elevation and the index finger located at a second elevation higher than the first elevation relative to the bottom surface. The generally hemispherical surface is further adapted for supporting the hollow of the hand so that the hand rests at an angle of forty-five degrees with respect to the support surface (i.e. the table) and with respect to the forearm in semipronation (i.e. half way between pronation and supination). The general hemispherical finger-supporting surface extends upwardly and laterally from one of the opposite sides. A thumb-supporting surface is provided for supporting the thumb of the hand, so that the mouse is securely gripped between the thumb and the fingers where the thumb supporting surface is disposed opposite the generally hemispherical finger-supporting surface without effort. The generally hemispherical finger-supporting surface and the thumb-supporting surface cooperate such that the hand is supported in the physiological position on the mouse. This aspect, which is an important part of the position of function, is the most characteristic quality of the human hand. The work of the hand in opposition is characteristic of humans and must be preserved at all costs.
In the preferred embodiment, the generally hemispherical surface merges into a hypothenar depression for supporting the hypothenar eminence of the hand, and a thenar depression for supporting the thenar eminence of the hand. Between the two eminences (thenar and hypothenar) exists a depression. Its corresponding and complementary form is shown with the eminence that we will call xe2x80x9cposterior prolongationxe2x80x9d and that is depicted in the appended drawings and described in greater detail below. A raised fork is disposed above the generally hemispherical surface for placing the fingers of the hand into a pincer position.